This application is directed generally to fittings for pipe, tubing and the like, and more particularly to a new and improved end fitting for connecting plastic pipe segments.
In natural gas distribution networks and other large fluid conveying systems wherein plastic pipe is utilized, it is frequently necessary to couple the end of one plastic pipe segment to the end of another pipe segment, or to a source, or to a service head or other utilization means. Fittings provided in such systems for this purpose must be capable of withstanding large axial stresses without compromise to their sealing capabilities, since the lengths of pipe to which the fittings are attached may extend hundreds of feet and therefore be subject to large temperature-induced length variations, which may amount to as much as one inch per hundred feet per 10.degree. F change in temperature. Furthermore, such fittings must be capable of rapid assembly by relatively unskilled workers, preferably without being disassembled, since the pipes and fittings in such distribution networks are ordinarily buried beneath the ground.
The present invention is directed to a pipe end fitting which meets these requirements, and which can be economically formed from plastic, nylon or similar materials by conventional molding techniques.
Accordingly, it is a general object of the present invention to provide a new and improved fitting for the end of a pipe.
It is another object of the present invention to provide a new and improved fitting which can be assembled on the end of a pipe without disassembly, and which provides improved capability to withstand high axial stresses.
It is another object of the present invention to provide a new and improved end fitting for a pipe segment which can be economically formed from plastic, nylon or similar materials by conventional techniques.
It is another object of the present invention to provide a new and improved fitting for the end of a plastic pipe having an electrically conductive inner liner, and which provides means for maintaining electrical continuity between the liners of adjacent pipe sections.